Oil pressure dropping a few PSI at idle after 1000 miles on the oil is from the oil viscosity changing from use, not the filter loading up. The PD oil pump is still moving the same volume of oil at idle regardless of the filter loading or oil viscosity changes. And highly doubt the pump is in pressure relief at idle. If the the oil temperature and flow volume is constant, and the oil pressure goes down, then the viscosity had to go down from some shearing.
Filter size: yesteryear vs today
- Thread starter dwasifar
- Start date
My recent UOA showed the ending oil viscosity to be virtually unchanged from its virgin state.
2020 Ram 1500 5.7 eTorque, Mobil 1 5W-20, 3200 miles
First run of M1 5W-20. Mix of city and highway driving. Prior service intervals have been around 3K. The oil cooler was replaced ~5k prior to this sample.
bobistheoilguy.com
Last edited:
You have a virgin oil UOA on the same bottle?
Since your truck is a 2020, I'm assuming it has a variable displacement oil pump? How it it controlled by the computer if so?
I’m going by this:
The fill in my sample was SN+ and was from around the same timeframe.
The pressure drop issue with filters in HEMI and late model LS applications is somewhat of a known issue with TSB’s published on it. It is a real issue. The root causes of it are unknown, so I wouldn’t go as far as indirectly saying that it is an impossible issue.
If going by that, there was a 0.2 cSt decrease. Plus, how do you know the oil temperature in you engine is always exactly the same at idle ... have an accurate digital oil temperature gauge on the dash?
Got a link to the TSB? ... I'd like to see what they say about it. I highly doubt any oil filter is going to load up in 1000 miles enough to cause any PD oil pump to hit pressure relief and drop the oil pressure at idle. Something strange going on.
BITOG is a place that by it's nature discusses and rediscusses topics ad infinitum.
I have never seen a thread on this topic until @billt460 created this one.
That leads me to believe that the supposed problem isn't widespread or a design or materials of construction issue.
That then takes us back to the user, @billt460 .
Why is the product so fundamentally flawed when he uses it but seems quite adequate for the preponderance of other members here?
And nevermind the multiple tropes that everything was better in the old days, bigger is better, thicker gage cans are better, etc.....
What a crock...
This mindset is stuck in the 1970s, where it needs to remain.
Any engineer worth his salt understands that designing a product fit for purpose is the goal of an engineering mindset, not bigger by definition is better.
Sheesh!!!
I have never seen a thread on this topic until @billt460 created this one.
That leads me to believe that the supposed problem isn't widespread or a design or materials of construction issue.
That then takes us back to the user, @billt460 .
Why is the product so fundamentally flawed when he uses it but seems quite adequate for the preponderance of other members here?
And nevermind the multiple tropes that everything was better in the old days, bigger is better, thicker gage cans are better, etc.....
What a crock...
This mindset is stuck in the 1970s, where it needs to remain.
Any engineer worth his salt understands that designing a product fit for purpose is the goal of an engineering mindset, not bigger by definition is better.
Sheesh!!!
OVERKILL
$100 Site Donor 2021
The HEMI does not have a variable displacement pump.
Yes, my measurements have always been at the same ~220f mark. I have a digital oil temp display.
The issue is not exclusive to Amsoil. It can happen with any of the high efficiency filters. Forum members have reported the issue with other brands as well.
OVERKILL
$100 Site Donor 2021
Did you C&P that filter? Visual inspection should be enough to confirm if the media is loading up or not.
Unfortunately, I did not. However, I am nearing 3K miles on a Fram Ultra and can save that one for photos.
OVERKILL
$100 Site Donor 2021
Perfect! I C&P'd the one from my wife's 5.7:
Fram Ultra XG2 (OG) C&P (11,716km)
This is the most recent filter off our 2019 RAM 1500 Sport with the 5.7L which sees mixed driving with a bias towards in town. Oil used was M1 EP 0w-20 and it was in there for 11,716Km (7,280 miles), changed when the OLM hit 0%. Despite propping the ADBV open with a screw, there was still...
bobistheoilguy.com
And my 6.4L:
Fram Ultra XG2 (OG) C&P (9,584km)
This is the first Ultra off my 2020 SRT (#2) that I purchased in September of 2020. I changed out the FF and factory filter at 1,912Km. This filter shows a bit of break-in debris in it and has been on the vehicle for 9,584km (5,955 miles). This filter was purchased, as part of a set that I...
bobistheoilguy.com
While both were quite dark, there wasn't any carbonaceous build-up in them, though you can see some in the bottom of the can from the 5.7L.
The oil on the 6.4L was clearly darker, even though the run was shorter. The bigger bores and performance-oriented programming I'm sure don't help.
The TSB only mentions an Amsoil filter, no mention of the Mopar OEM filter.
So have you or anyone else just changed the oil filter at 1000 miles with the same exact filter, but not change the oil, and see the oil pressure increase by a couple of PSI at idle and at the exact same oil temperature.
I just can't believe that any oil filter is clogging enough to make the oil pressure change that much at idle with a non-variable volume PD oil pump.
What's the oil pressure readings at 2000, 3000 and 4000 RPM at 1000 miles compared to the same readings (same oil temps) taken right after an oil and filter change?
Oil filters got snaller when they went to the 3000 mile oil changes.
Not many, if any car manufacturers today recommend a 3000 mille oil change.
That sounds like lore. Is there data to back this claim?
Not to go too far off topic, but…
With the increasing engine issues in recent years and the GDI-related challenges, a 3k oil change may make more sense than ever.
I know. But I'm thinking 20-30 years ago when 3000 mile oil changes were being pushed is when oil filters got smaller.
OVERKILL
$100 Site Donor 2021
Figured I'd post these for you here:
1. Hot at idle in gear:
2. Driving pressure going down the road:
Oil was installed November 18th, 2021 at 49,044km, so it has 5,477km on it (3,400 miles).
I'll do a before/after at my upcoming oil change.
